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NEWS - Vaisala - a global leader in environmental and ... · PDF fileVaisala News magazine celebrates ... Polyacrylamide drying at Kemira is a ... is very difficult to forecast due

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  • The road to efficient and cost-effective winter road maintenance / Page 4

    Vaisala News magazine celebrates its 50th anniversary / Page 8

    Vaisala launches the development of a new reference radiosonde for climate change observations / Page 16

    Are you prepared for safety hazards caused by wind shear? / Page 4

    Measuring process humidity for optimal product quality / Page 6

    Flying into the storm - Greenland Flow Distortion experiment / Page 16





  • Cover photo: Shutterstock / Editor-in-Chief: Marikka Nevamki

    Publisher: Vaisala Oyj, P.O. Box 26, FI-00421 Helsinki, FINLAND

    Phone (int.): + 358989491 / Telefax: + 358989492227

    Internet: / Layout: Sampo Korkeila

    Printed in Finland by: SP-Paino / ISSN 1238-2388

    Vaisala in brief

    Vaisala is a global leader in environmental and industrial measurement. Building on more than 70 years of experience, Vaisala contributes to a better quality of life by providing a comprehensive range of innovative observation and measurement products and services for meteorology, weather critical operations and controlled environments. Headquartered in Finland, Vaisala employs over 1200 professionals worldwide and is listed on the NASDAQ OMX Helsinki.

    180/2009Contents 3 Reliable partner in turbulent times

    4 Are you prepared for safety hazards caused by wind shear?

    6 Measuring process humidity for optimal product quality

    8 transformerLIFE Centre researchers choose Vaisala sensors

    10 Vaisala participates in the biggest meteorological modernization project in the Russian history

    11 Forecasting extreme events of rain

    12 Humidity measurement in cleanrooms

    15 Building automation solutions for the future

    16 Flying into the storm

    18 AMS President 2008: looking back

    20 Road safety taken to a new level in New Zealand

    22 Three decades of superior performance

    24 Brazil contributes to research in the Antarctic

    26 Vaisalas first Corporate Responsibility report published

    27 Briefly noted

    Weather plays a significant role in avia-tion safety. Wind shear is one of the most dangerous - and least known - weather phenomena in aviation. Page 4

    Polyacrylamide drying at Kemira is a complex process, which demands strictly regulated humidity and temperature condi-tions. Page 6

    Greenland is a massive obstacle to the atmospheric flow and the low level air prefers to flow along and around Greenland if possible, rather than attempting to flow over the ice sheet. Page 16


  • Kjell Forsn

    Presidents column

    The world economy is in turmoil. Times of economic prosperity have always eventually been followed by a downturn - yet when it happens it always seems to take everyone by surprise. When times are good, too often short-term gains are preferred over long-term planning, and consideration about consequences is not high on the agenda. But when times are tough, insecurity raises its head, and suddenly your ability for long-term planning and sustainable business practices becomes much more transparent. Reliability, conti-nuity and experience reign supreme, providing peace-of-mind and sustain-able operations for the long-term.

    Vaisalas expertise is based on exactly this kind of reliability, conti-nuity and experience. We have been

    in business for over 70 years, and will continue to do so through many ups and downs yet to come. Our business is built on innovation, solid profes-sional know-how and technological superiority, combined with a good understanding of our customers requirements. This combination has taken us through many hard times with determination and persistence. Our strong heritage, still present in the company culture today, paves the way for continuity and healthy company values. Our customers know that when they buy Vaisala, they will have our support also tomorrow, and the day after.

    Reliability alone is not enough. As times change, businesses need to be able grow and capitalize on this change. Our innovative approach to

    science and technology has allowed us to adapt to new business fields and needs.

    It is our customers trust that has allowed us to grow and prosper. Trust is earned through deeds and competence, and if lost, it is extremely hard to regain. I want to express my heartfelt thanks to all of you for this trust - it is most valuable to us, and we intend to earn it through our actions everyday.

    Reliable partner in turbulent times


  • Juhani Polvinen / Application Manager / Vaisala / Helsinki, Finland

    Are you prepared for safety hazards caused by wind shear?Weather plays a significant role in aviation safety. Some 30% of all fatal

    accidents are caused by or related to weather (ICAO). Wind shear is one of the

    most dangerous - and least known - weather phenomena in aviation.

    Air traffic controllers usually have no means of directly detecting a low-level wind shear hazard. It may take even the most experienced pilots by surprise, and put them in a situation where the wrong decisions can have disastrous effects. 831 fatalities were recorded to have been caused by wind shear between 1956-1994 (FAA, NTSB Records, & Fujita), or 700 fatalities between 1970-1985 (ICAO). More recent statistics are harder to find, but the phenomenon has not disappeared. Wind shear continues to pose a threat to aviation safety all around the world. According to the

    US Aviation Safety Network (ASN), at least two major accidents were caused by wind shear between 1990-2000, resulting in over 90 fatalities. Also in many recent accidents, wind shear has been suspected to be a strong contributing factor - such as in the case of the TANS Airlines crash in Peru (2005), or FedEx cargo plane crash in Japan (2009).

    Wind shear is a term referring to rapidly changing winds. It is a small scale meteorological phenomenon, which occurs over a very small distance. It is usually connected to rapid changes in specific weather

    conditions - for example, sea and land breeze, jet streams (fast flowing, narrow air currents), weather fronts, showers or thunderstorms. It has also been noted to commonly occur near mountains and coastlines. The most dangerous type of wind shear is caused by convective weather. It is very difficult to forecast due to its local nature.

    Wind shear poses the greatest danger to aircraft during takeoff and landing. Airplane pilots generally regard significant wind shear to be a horizontal change in airspeed of 30 knots (15 m/s) for light aircraft, and near 45 knots (22 m/s) for airliners (FAA).

    Although wind shear as a meteo-rological phenomenon has been recognized in aviation from the late 60s, it is still not fully understood today. Many airports suffer the effects of wind shear, but airport authorities have little information about the phenomenon and how to address it.

    One of the first great eye-openers was the Boeing 727 accident at the JFK Airport in 1975, which led to systematic studies on wind shear. Tetsuya Theodore Fujita pioneered the study of wind shear and its effects. However, it wasnt until 1997 that ICAO formally established a Low-Level Wind Shear and Turbulence


  • Group to promote global awareness about the phenomenon.

    Challenge to pilots and aircraft safety

    Microbursts and wind shear go hand in hand. Microbursts are small scale intense downdrafts which, on reaching the surface, spread outward in all directions from the downdraft center. This causes the presence of both vertical and horizontal wind shears. Microbursts spread radially on the ground, causing rapid changes in wind direction and speed. They are associated with cumulonimbus clouds, as well as line squalls (severe thunderstorms). A distinction can be made between a wet microburst which consists of precipitation and a dry microburst which consists of virga - that is, precipitation that evaporates before reaching the ground. Dry microbursts present a more difficult problem because pilots have no visual clue of their occur-rence, and weather radars cannot see them either.

    Wind shear and microbursts are among the most dangerous of all weather-related threats to flying. The unpredictable changes in wind speed and direction make it difficult to control the aircraft, with headwinds, tailwinds and up and down drafts all in quick succession. At worst, it can cause a sudden and dramatic loss in height, and result in a serious accident.

    How to address wind shear safety risks?

    When wind shear occurs below 2,000 ft altitude, it is called low-level wind shear. Many airports prone to micro-burst and wind shear are still lacking adequate solutions to mitigate this threat.

    The first step in addressing safety hazards caused by wind shear is to investigate the likelihood of the occurrence of the phenomenon at the airport in question. If a problem is recognized, different options for solving it need to be investigated in order to find the optimal solution. Each airport is unique. This work is best carried out in cooperation with the airport authorities and an expert organization with deep under-standing of the phenomenon.

    Once the existence of low-level wind shear has been verified through studying the weather conditions at the airport, the next step is to specify the optimal wind measurement site locations and measurement mast heights by studying the topology and obstructions in the area. After this, the required system and interfaces can be specified by investigating the existing infrastructure.

    A Low-Level Wind Shear Alert System (LLWAS) comprises wind speed and direction sensors sited around the runway, and connected to a data collection package at the